1. Field of the Invention
The present invention relates to an image data processor and an image data processing method for applying a conversion process to an ordinary image to obtain an image to which a special effect processing is applied.
2. Description of the Related Art
FIG. 8 is a block diagram schematically showing a structure of a conventional image capturing device. The image capturing device shown in FIG. 8 comprises a CCD image sensor (solid-state image capturing element) 1, a CCD driver circuit 2, a timing controller circuit 3, an analog signal processor circuit 4, an A/D converter circuit 5, and a digital signal processor circuit 6.
The solid-state image capturing element 1 has a light receiving region which includes a plurality of light receiving pixels arranged in a matrix, receives, in each light receiving pixel, light incident on the light receiving region, and generates information charges through photoelectric conversion. The solid-state image capturing element 1 accumulates, in each light receiving pixel, the information charges during a predetermined accumulation period and then sequentially transfers the accumulated charges through a plurality of shift registers. The transferred charges are converted into voltage values by an output unit provided on the final stage of the transfer route and is output as an image signal Y0(t).
The CCD driver circuit 2 generates a plurality of clock pulses synchronized with a vertical synchronization signal VT and a horizontal synchronization signal HT supplied from the timing controller circuit 3 as will be described below. The CCD driver circuit 2 supplies the generated clock pulses to the solid-state image capturing element 1 and drives the solid-state image capturing element 1 to sequentially transfer the information charges accumulated in the plurality of light receiving pixels.
The timing controller circuit 3 counts a reference clock CK and generates a vertical synchronization signal VT and a horizontal synchronization signal HT and determines the vertical scanning period and the horizontal scanning period for the solid-state image capturing element 1. For example, when the device functions according to the NTSC standards, the timing controller circuit 3 divides a reference clock CK having a frequency which is 4 times the frequency 3.58 MHz of a color subcarrier wave used in signal processing steps into 1/910 to generate a horizontal synchronization signal HT. Similarly, the timing controller 3 divides the horizontal synchronization signal HT into 2/525 to generate a vertical synchronization signal VT.
The analog signal processor circuit 4 applies an analog signal process such as a CDS (Correlated Double Sampling) and AGC (Automatic Gain Control) to the image signal Y0(t) output from the solid-state image capturing element 1 to generate an image signal Y1(t). The A/D converter circuit 5 digitizes the image signal Y1(t) in synchronization with the operation timing of the solid-state image capturing element 1 to convert the signal to a digital signal and outputs the digital signal as image data Y0(n).
The digital signal processor circuit 6 applies a digital signal process such as color separation and matrix calculation to the image data Y0(n) output from the A/D converter circuit 5 and generates image data Y1(n) which includes brightness data and color-difference data.
The image data Y1(n) output from the digital signal processor circuit 6 is stored in a storage medium such as a semiconductor memory and a magnetic disk, and, at the same time, is supplied to a driver device for driving a display device such as an LCD panel.
In an image capturing device as described, additional processes are applied such as, for example, a process to obtain a binary image by comparing the data of each pixel in the image data to a threshold value and a process to apply differentiation in the vertical or horizontal direction of the pixel data, and to display an image according to the differentiated values to thereby display an image while emphasizing the outline of the image. In addition, various signaling processes for obtaining various replayed images have been proposed.